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Biomedical subjects

K Hara

Publications and source records attributed to K Hara.

At least 55 records · Page 3Linked to original sources
PubMed2004

Effect of Japanese horseradish oil on methane production and ruminal fermentation in vitro and in steers.

The effects of alpha-cyclodextrin-horseradish oil complex (CD-HR) on methane production and ruminal fermentation were studied in vitro and in steers. In the in vitro study, diluted ruminal fluid (30 mL) was incubated anaerobically at 38 degrees C for 6 h with or without CD-HR, using cornstarch as substrate. The CD-HR was added at various concentrations (0, 0.17, 0.85 and 1.7 g/L). Treatment affected neither the pH of the medium nor the number of protozoa. Total VFA increased in a linear manner (P = 0.02), and NH3-N decreased quadratically (P = 0.04) as the concentration of CD-HR increased from 0.17 g/L to 1.7 g/L. Molar proportions of acetate decreased in a linear manner (P = 0.03), and propionate increased linearly (P = 0.008) with increasing concentrations of CD-HR. Production of methane was inhibited up to 90%, whereas accumulation of dihydrogen was increased 36-fold by 1.7 g/L of CD-HR supplementation relative to controls. The effect of CD-HR on methane production, ruminal fermentation and microbes, and digestibility was further investigated in vivo using four Holstein steers in a crossover design. The CD-HR supplement was mixed into the concentrate portion of a (1.5:1) Sudangrass hay plus concentrate mixture that was fed twice daily to the steers. Ruminal samples were collected 0, 2, and 5 h after the morning feeding. No effects of CD-HR supplementation on ruminal pH (P = 0.63) or protozoal numbers (P = 0.44) were observed. Molar proportion of acetate was decreased (P = 0.04) and propionate was increased (P = 0.005) by CD-HR treatment. Molar proportion of butyrate was increased (P = 0.05) in CD-HR-supplemented steers. Ruminal NH3-N was decreased (P = 0.05) by treatment. Blood plasma glucose concentration was increased (P = 0.02) and urea-N was decreased (P = 0.04) with CD-HR supplementation. Daily DMI was decreased (P = 0.04), and apparent digestibility of DM (P = 0.13), NDF (P = 0.14), and CP tended (P = 0.14) to be increased by treatment. Methane production was decreased (P = 0.03) by 19%, and the number of methanogens was also decreased (P = 0.03). Although N retention (P = 0.11), total viable bacteria (P = 0.15), and sulfate-reducing bacteria (P = 0.17) were not significantly altered by treatment, tendencies for increases were noted with CD-HR supplementation. The number of cellulolytic (P = 0.38) and acetogenic bacteria (P = 0.32) remained unchanged by treatment. These results indicate that CD-HR supplementation can be used to decrease methane production in steers.

Animals↗
PubMed2003

Measurement of time-dependent CP-violating asymmetries in B0-->phiK(0)S, K+K-K0(S), and eta'K0(S) decays.

We present an improved measurement of CP-violation parameters in B0-->phiK(0)(S), K(+)K(-)K(0)(S), and eta(')K(0)(S) decays based on a 140 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB energy-asymmetric e(+)e(-) collider. One neutral B meson is fully reconstructed in one of the specified decay channels, and the flavor of the accompanying B meson is identified from its decay products. CP-violation parameters for each of the three modes are obtained from the asymmetries in the distributions of the proper-time intervals between the two B decays. We find that the observed CP asymmetry in the B-->phiK(0)(S) decay differs from the standard model (SM) expectation by 3.5 standard deviations, while the other cases are consistent with the SM.

Journal Article↗
PubMed2003

Leukocyte 8-hydroxydeoxyguanosine and aromatic DNA adduct in coke-oven workers with polycyclic aromatic hydrocarbon exposure.

OBJECTIVE: To investigate the potential for exposure to polycyclic aromatic hydrocarbons (PAHs) to induce oxidative DNA damage, we conducted a cross-sectional study in coke-oven workers employed at an iron-steel factory. METHODS: The study population contained 119 coke-oven workers from different work areas of the oven and 38 controls. Personal information on age, employment duration, smoking habit and alcohol consumption was obtained at an interview. Leukocyte 8-hydroxydeoxyguanosine (8-OHdG) was measured by high performance liquid chromatography with electrochemical detection. Leukocyte aromatic DNA adducts as effective dose, and urinary 1-hydroxypyren as internal dose, were also measured, and used to analyze the relationship of 8-OHdG with other biomarkers for PAH exposure, tobacco smoke and alcohol consumption. RESULTS: The leukocyte 8-OHdG revealed a wide inter-individual variation. The highest 8-OHdG level was detected in bottom-workers of the coke-oven. There were significant differences among the four different work areas ( P=0.02). We could not find significant correlation between 8-OHdG levels and urinary 1-hydroxypyrene, but a weakly positive correlation was found between 8-OHdG and leukocyte aromatic DNA adducts among all subjects (r=0.19 P=0.03). We could not observe any effect of smoking and alcohol drinking on 8-OHdG production. CONCLUSION: We could not find clear evidence that PAH exposure induces oxidative DNA damage.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2003

Excitation and decay of the isovector giant monopole resonances via the 208Pb(3He,t p) reaction at 410 MeV.

The excitation and subsequent proton decay of the isovector spin-flip giant monopole resonance (IVSGMR) is studied via the 208Pb(3He,t) reaction at 410 MeV. In the inclusive spectrum (60+/-5)% of the non-energy-weighted sum-rule strength for this 2 variant Planck's over 2h omega resonance was found in the region 29<Ex(208Bi)<51 MeV. The central excitation energy and width of the IVSGMR are 37+/-1 MeV and 14+/-3 MeV, respectively. It is found that the branching ratio for proton decay is (52+/-12)% and that the deep neutron-hole states in 207Pb are strongly fed.

Journal Article↗
PubMed2003

Ser624 of the PA subunit of influenza A virus is not essential for viral growth in cells and mice, but required for the maximal viral growth.

Serine at position 624 of PA subunit of the Influenza A virus RNA polymerase is the active site of a serine protease domain. To examine the role of this protease activity in the viral infection cycle, we compared the growth and the pathogenesis of influenza A/WSN/33 (WSN) and the virus encoding a PA with a S624A mutation (S624A virus), which were generated by the plasmid-based rescue system. The growth of S624A virus was less extensive than that of WSN in cells. The LD50 of S624A virus and WSN for intranasal infection in Balb/C mice was 4.0 x 10(4) and 9.3 x 10(3) PFU, respectively. That for intracranial infection was 460 and 200 PFU, respectively. These data indicated that Ser624, the active site of the serine protease activity of PA, is not essential for viral growth and pathogenesis, but is required for the maximal viral growth.

Animals↗
PubMed2003

An in vitro interethnic comparison of monoamine oxidase activities between Japanese and Caucasian livers using rizatriptan, a serotonin receptor 1B/1D agonist, as a model drug.

AIMS: Monoamine oxidase (MAO) is located in human liver, and catalyses the oxidative deamination step of many xenobiotics. However, whether there exists an interethnic difference in MAO activities has, to our knowledge, not been clarified. We aimed to assess the MAO type A (MAO-A) involvement in the metabolic pathway of rizatriptan (RIZ), an antimigraine 5-hydroxytryptamine (5-HT)1B/1D agonist, and the interethnic difference in MAO activities between Caucasians and Japanese using RIZ as a model drug in in vitro experiments. METHODS: Oxidative deaminase activities were determined with the subcellular fractions of Japanese livers and the microsomal fraction of Caucasian livers using RIZ, 5-HT (MAO-A substrate) and 2-phenylethylamine (PEA) (MAO-B substrate) as substrates. RESULTS: The oxidative deaminase activities of RIZ vs. 5-HT were highly (r = 0.87 and 0.96, P < 0.001) correlated with each other in both the microsomal and mitochondrial fractions of Japanese livers. Subsequent results were obtained from in vitro experiments using liver microsomes based upon these findings. The oxidative deaminase activities of RIZ were inhibited completely by the nanomolar-order concentration of clorgyline and Ro 41-1049 (MAO-A selective inhibitors), but not by that of Ro 16-6491 (MAO-B selective inhibitor). The majority of the mean Michaelis-Menten values for three substrates toward MAO obtained from six Japanese and six Caucasian liver microsomes reached no significant differences between the two ethnic groups. The mean microsomal oxidative deaminase activities assessed in 18 Japanese and 20 Caucasian livers using the three substrates also showed no significant differences between the two ethnic groups. CONCLUSIONS: RIZ is mainly metabolized by MAO-A and the in vitro oxidative deaminase activities mediated via MAO-A and -B do not appear to differ between Japanese and Caucasians.

Asian People↗
PubMed2003

[Pulmonary adenocarcinoma of the fetal lung type; report of a case].

An asynptomatic 58-year-old male was admitted to the hospital because of an abnormal nodule in the left lung field on screening chest X-ray. Chest computed tomography (CT) showed a tumor shadow mass in the left lower lobe. Open biopsy was performed to diagnose the mass. The cytological diagnosis was low-grade malignant adenocarcinoma, underwent left lower lobectomy. The histological diagnosis was pulmonary adenocarcinoma of the fetal lung type which was one of pulmonary blastoma (PB). Recently, the concept of pulmonary blastoma has changed. It will be useful to investigate the old PB's case reports to classify new concept.

Adenocarcinoma↗
PubMed2002

Measurement of the B(0)-B(0) mixing parameter Deltam(d) using semileptonic B0 decays.

We present a measurement of the B0-Bmacr;(0) mixing parameter Deltam(d) using neutral B meson pairs in a 29.1 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We exclusively reconstruct one neutral B meson in the semileptonic B0-->D(*-)l(+)nu decay mode and identify the flavor of the accompanying B meson from its decay products. From the distribution of the time intervals between the two flavor-tagged B meson decay points, we obtain Deltam(d)=(0.494+/-0.012+/-0.015) ps(-1), where the first error is statistical and the second error is systematic.

Journal Article↗
PubMed2002

Study of CP-violating asymmetries in B0-->pi(+)pi(-) decays.

We present a measurement of CP-violating asymmetries in B0-->pi(+)pi(-) decays based on a 41.8 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We fully reconstruct one neutral B meson as a B0-->pi(+)pi(-) CP eigenstate and identify the flavor of the accompanying B meson from its decay products. From the asymmetry in the distribution of the time intervals between the two B meson decay points, we obtain the CP-violating asymmetry parameters S(pipi)=-1.21(+0.38)(-0.27)(stat)+0.16-0.13(syst) and A(pipi)=+0.94(+0.25)(-0.31)(stat)+/-0.09(syst).

Journal Article↗
PubMed2002

Observation of chi(c2) production in B meson decay.

We report the first observation of chi(c2) production in B meson decays. We find an inclusive B-->chi(c2)X branching fraction of (1.80(+0.23)(-0.28)+/-0.26) x 10(-3). The data set, collected with the Belle detector at the KEKB e(+)e(-) collider, consists of 31.9 x 10(6) BB events. We also present branching fractions and momentum spectra for both chi(c1) and chi(c2) production.

Journal Article↗
PubMed2002

A genetic variation in the PGC-1 gene could confer insulin resistance and susceptibility to Type II diabetes.

AIMS/HYPOTHESIS: Peroxisome proliferator activated receptor gamma coactivator-1 (PGC-1), a transcriptional coactivator of the nuclear receptor PPARgamma, plays a role in adaptive thermogenesis and insulin sensitivity. Plasma fasting insulin has been linked to the chromosomal region where the PGC-1 gene is located. Thus, PGC-1 can be viewed as a functional and positional candidate for the susceptibility gene for Type II (non-insulin-dependent) diabetes mellitus. METHODS: After screening the PGC-1 gene for single nucleotide polymorphisms (SNPs), we performed an association study using the newly detected SNPs in 537 Type II diabetic patients and 417 non-diabetic subjects. RESULTS: We found three relatively frequent SNPs in the PGC-1 gene (IVS4-11T > C, Thr394Thr and Gly482Ser). There were significant differences in fasting insulin (Gly/Gly; 37.7 +/- 1.43, Gly/Ser; 40.2 +/- 1.21, Ser/Ser; 44.3 +/- 1.82 pmol/l, p = 0.018) and insulin resistance index (Gly/Gly; 1.48 +/- 0.06, Gly/Ser; 1.56 +/- 0.05, Ser/Ser; 1.75 +/- 0.08, p = 0.027) according to the genotype of the Gly482Ser polymorphism. The Thr394Thr - Gly482Ser haplotype was associated with Type II diabetes (p = 0.00003). CONCLUSION/INTERPRETATION. The results of this study suggested that the PGC-1 gene might be implicated in the pathogenesis of Type II diabetes.

Base Sequence↗
PubMed2002

Observation of B(+/-) --> p(-)pK(+/-).

We report the observation of the decay mode B(+/-) --> p(-)pK(+/-)based on an analysis of 29.4 fb(-1) of data collected by the Belle detector at KEKB. This is the first example of a b-->s transition with baryons in the final state. The p(-)p mass spectrum in this decay is inconsistent with phase space and is peaked at low mass. The branching fraction for this decay is measured to be B(B+/--->p(-)pK+/-) = [4.3(+1.1)(-0.9)(stat)+/-0.5(syst)]x 10(-6). We also report upper limits for the decays B(0)-->p(-)pK(S) and B(+/-)-->p(-)p pi(+/-).

Journal Article↗
PubMed2002

Precise measurement of B meson lifetimes with hadronic decay final states.

The lifetimes of the B(0) and B- mesons are extracted from 29.1 fb(-1) of data collected with the Belle detector at the KEK B factory. A fit to the decay length differences of neutral and charged B meson pairs, measured in events where one of the B mesons is fully reconstructed in several hadronic modes, yields tau(B(0)) = 1.554+/-0.030(stat)+/-0.019(syst) ps, tau(B-) = 1.695+/-0.026(stat)+/-0.015(syst) ps, and tau(B-)/tau(B(0)) = 1.091+/-0.023(stat)+/-0.014(syst).

Journal Article↗
PubMed2002

Measurement of the lifetime difference in D0 meson decays.

We report a measurement of the D0-D macro(0) mixing parameter y(CP) using 23.4 fb(-1) of data collected near the Upsilon(4S) resonance with the Belle detector at KEKB. y(CP) is measured from the lifetime difference of D0 mesons decaying into the K(-)pi(+) state and the CP-even eigenstate K(-)K(+). We find y(CP) = (-0.5+/-1.0(+0.7)(-0.8))x10(-2), where the first error is statistical and the second is systematic, corresponding to a 95% confidence interval -0.030<y(CP)<0.020.

Journal Article↗
PubMed2002

Observation of the color-suppressed decay B( 0)-->D(0)pi(0).

We report the first observation of color-suppressed B( 0)-->D(0)pi(0), D(*0)pi(0), D0eta, and D0omega decays, and evidence for B( 0)-->D(*0)eta and D(*0)omega. The branching fractions are B(B( 0)-->D0pi(0)) = (3.1 +/- 0.4 +/- 0.5)x10(-4), B(B( 0) -->D(*0)pi(0)) = (2.7(+0.8+0.5)(-0.7-0.6))x10(-4), B(B( 0) --> D0eta) = (1.4(+0.5)(-0.4) +/- 0.3)x10(-4), B(B( 0) --> D0omega) = (1.8 +/- 0.5(+0.4)(-0.3))x10(-4), and we set 90% confidence level upper limits of B(B( 0) --> D(*0)eta)<4.6 x 10(-4) and B(B( 0)-->D(*0)omega)<7.9 x 10(-4). The analysis is based on a data sample of 21.3 fb(-1) collected at the Upsilon(4S) resonance by the Belle detector at the KEKB e(+)e(-) collider.

Journal Article↗
PubMed2002

Production of prompt charmonia in e(+)e(-) annihilation at square root of s approximately equals 0.6 GeV.

The production of prompt J/psi, psi(2S), chi(c1), and chi(c2) is studied using a 32.4 fb(-1) data sample collected with the Belle detector at Upsilon(4S) and at 60 MeV below the resonance. The yield of prompt J/psi mesons in the Upsilon(4S) sample is compatible with that of continuum production; we set an upper limit B(Upsilon(4S)-->J/psiX) < 1.9 x 10(-4) at the 95% confidence level, and find sigma(e(+)e(-)-->J/psiX) = 1.47 plus/minus 0.10 plus/minus 0.13 pb. The cross sections for prompt psi(2S) and direct J/psi are measured. The J/psi momentum spectrum, production angle distribution, and polarization are studied.

Journal Article↗